Pressure testing a "Watchco" SM300

Archer

For my buddy Stas...and anyone else who may be interested, even though they don't dive...

I didn't want to post anything until I found these photos...but I knew I had tested at least one of these before, so after some digging, here you go. I'll start off by stating this is the second time the case was tested, because all of what you will see here is done with the case empty first, in case there is a failure. Then once the empty case passes, the movement is installed, and the test is repeated, so this is that second test. Start by using the dry testing machine, set to the dive watch program - it will use a -0.7 bar vacuum, and then a +10 bar pressure to test the watch, while carefully measuring the deflection of the case:



The watch passes both tests:



Now off to another room where the high pressure wet testing equipment is located:



The watch is placed in the testing chamber, and the chamber is filled with water:



The chamber is closed, and the watch is left with no additional pressure applied for 30 minutes - note that I hadn't wound the watch, so it wasn't running:



After 30 minutes the pressure is increased. This particular equipment is capable of testing to 125 Bar, but that is for very rigid dive watches with thick sapphire crystals. In this case I used 25 Bar, so 200 m rated depth +25% safety margin as per Omega standards for this kind of testing of their proper dive watches - here is the pressure gauge:



Shot of the watch in the chamber and you can see the pressure gauge also:



I leave it at this pressure for one hour, then lower the pressure back down to zero, and leave it in the chamber for another 30 minutes:



The watch is then removed from the testing chamber:



Placed on a heating plate that will bring the temperature of the watch to 47 degrees C - this takes 30 minutes:



After 30 minutes have elapsed, a drop of cool water is placed on the crystal, and left for one minute:



It is then wiped away, and the crystal is examined under a loupe to ensure that no condensation has formed on the underside - seeing none, the watch has passed:



et voilà

Cheers, Al

K korenje

you use cheap manometer with 63mm diameter which questionable precision... didn't expect this in watch testing equipment.

dsio

@Archer this may sound like an odd question but have you ever / often for curiosity sake pushed a case beyond its limits intentional to failure to see when / where that failure occurs? Like taking a sealed but empty SM300 and going above the 25%, and continuing until either the crystal caseback or crown finally goes pop?